1. Field of the Invention
The present invention relates to an information processing apparatus for optically recording, reproducing, and erasing information using an optomagnetic effect.
2. Description of the Related Art
Various types of optomagnetic recording/reproduction apparatuses using optomagnetic media are available as information recording/reproduction apparatuses. Examples of the optomagnetic recording/reproduction apparatus of this type are an external memory of a computer, a rewritable video disk drive, an image file apparatus, a compact disk drive of a DAD type which can perform both reproduction and recording, and a rewritable high-density recording magnetic card.
The optomagnetic recording/reproduction apparatus comprises an optical head for recording, reproducing, and erasing information, a medium for recording information, and a magnetic field generator for applying a magnetic field.
The optomagnetic recording/reproduction apparatus is operated as follows. First, a static magnetic field is perpendicularly applied to a recording film surface of an information recording medium. A focused light beam is radiated on recording tracks on the recording film surface of the information recording medium to heat the recording film surface up to a temperature exceeding a Curie point or a temperature at which a coercive force is smaller than an external magnetic field. When the irradiated region of the recording film surface is heated, a magnetic moment of a magnetic domain in the region is inverted, thereby recording or erasing information.
In conventional apparatuses, however, a focused light beam is scanned on the recording tracks on the information recording film to perform erasure of information. Therefore, even when all of information recorded on the information recording film is to be erased, for example, a light beam must be radiated on and a magnetic field must be applied to each track, resulting in a very long erasure time.